scholarly journals Synthesis and Characterization of Boron Trifluoride Doped High Performance Polyaniline

2012 ◽  
Vol 9 (4) ◽  
pp. 2332-2337 ◽  
Author(s):  
K. Basavaiah ◽  
D. Samsonu ◽  
A. V. Prasada Rao
Keyword(s):  
Boron Trifluoride ◽  
High Performance ◽  
Heterogeneous Reaction ◽  
Reaction Medium ◽  
Emeraldine Base ◽  
Step Method ◽  
Base Form ◽  
Polymerization Method ◽  
Thermal Stability Of

We report simple synthesis of boron trifluoride (BF3) doped defect free high performance polyaniline (HPPANI) in two step method. Firstly, HPPANI was prepared via self-stabilization dispersion polymerization method in a heterogeneous reaction medium. Second step involves doping of emeraldine base form of HPPANI with boron trifluoride under reduced vacuum. The resultants BF3doped HPPANI have been well characterized by using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetry. The spectroscopic data indicated that the interaction between HPPANI and BF3.Thermogravimetry studies revealed that the BF3 doping improved the thermal stability of defects free PANI.

scholarly journals Synthesis and Characterization of a Novel Class of Lewis Acid Doped Tetraaniline

2012 ◽  
Vol 9 (3) ◽  
pp. 1085-1090 ◽  
Author(s):  
K. Basavaiah ◽  
A. V. Prasada Rao
Keyword(s):  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Emeraldine Base ◽  
X Ray Diffraction ◽  
Step Method ◽  
Ammonium Persulphate ◽  
Novel Structure ◽  
Base Form ◽  
Diffraction Patterns

Boron trifluoride (BF3) doped tetraaniline with novel structure were successfully synthesized via two step method. In the first step, emeraldine base form tetraaniline was synthesized via oxidative chemical polymerization of N-phenyl-1, 4-phenylenediamine using ammonium persulphate as oxidant. In the second step involves control BF3doping of tetraaniline using boron trifluoride etherate. As synthesized BF3doped tetraaniline have been well characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction patterns (XRD), and scanning electron microscopy (SEM) and thermogravimetry. Thermogravimetry studies revealed that the BF3doping improved the thermal stability of tetraaniline.

Characterization of Poly(o-methoxyaniline) Emeraldine-base form obtained at different time neutralization

2014 ◽  
Vol 1063 ◽  
pp. 336-340 ◽  
Author(s):  
Edgar A. Sanches ◽  
Ludson C.A. Gomes ◽  
Juliana C. Soares ◽  
Geisiane R. da Silva ◽  
Yvonne P. Mascarenhas
Keyword(s):  
Emeraldine Base ◽  
Base Form

scholarly journals Chemical Oxidative Synthesis and Characteristion of Organica acid Doped Soluble Conducting Poly(o-anisidine)

2009 ◽  
Vol 3 (2) ◽  
pp. 95-99
Author(s):  
Vasant Chabukswar ◽  
◽  
Ganesh Sable ◽  
Keyword(s):  
Acrylic Acid ◽  
Tartaric Acid ◽  
Sharp Peak ◽  
Emeraldine Base ◽  
Spectral Studies ◽  
Ammonia Vapor ◽  
Emeraldine Salt ◽  
Base Form ◽  
Doped Polymer ◽  
Polymerization Method

Synthesis of poly(o-anisidine) with and without acrylic acid doping is carried out by chemical oxidative polymerization method. This is a new polymerization method for the direct synthesis of the emeraldine salt of poly(o-anisidine), i.e. it is directly soluble in known organic solvent such as m-cresol, N-methyl pyrrolidone (NMP), DMSO, DMF, etc. without the need for a conversion of salt phase to base form. The reaction is unique since it eliminates the post processing step which involves neutralization of emeraldine salt to form emeraldine base and again reprotonating the base with a secondary protonic acid. The acrylic acid doped polymer prepared using tartaric acid is comparatively more soluble in m-cresol and NMP than the poly(o-anisidine) prepared without acrylic acid. UV-visible spectra for acrylic acid doped poly(o-anisidine) reveals the coil conformation at higher wavelength ~800–1000 nm along with sharp peak ~440 nm, which may be attributed to secondary doping due to extended coil conformation. Whereas in the presence of NMP as a solvent, the extended tail at higher wavelength disappears while a sharp peak (~630 nm) is observed representing the polymer insulting emeraldine base form. This fact confirms the effect of the solvent on the polymer properties. This is further manifested by the FT-IR spectral studies. Broad and intense band at ~3300–3200cm–1 and 1100–1200 cm–1 in acrylic acid doped polymer accounts for higher degree of doping. The conductivity of acrylic acid doped poly(o-anisidine) is greater than poly(o-anisidine) without acrylic acid. The change in resistance of tartaric acid doped poly(o-anisidine) prepared in acrylic acid media upon its exposure to ammonia vapor suggests the applicability of these polymeric materials for ammonia.

scholarly journals Preparation and characterization of a new polyaniline salt with good conductivity and great solubility in dimethyl sulfoxyde

2015 ◽  
Vol 80 (11) ◽  
pp. 1435-1448 ◽  
Author(s):  
Hichem Zeghioud ◽  
Saad Lamouri ◽  
Yasmine Mahmoud ◽  
Tarik Hadj-Ali
Keyword(s):  
Conductivity Measurement ◽  
Emeraldine Base ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
A Value ◽  
Base Form ◽  
Visible Spectra ◽  
Doped Polyaniline ◽  
Dispersing Medium

In this study, we propose a novel conducting and soluble polyaniline salt prepared by chemical polymerization in the presence of new doping agent (IAs). This last is prepared by sulphonation of itaconic acid (IA) with concentrated sulphuric acid in THF. The obtained doped polyaniline (PANI-IAs) is extremely soluble in dimethyl sulfoxyde (DMSO) at room temperature, in which the solubility reach 44 mg mL-1. The conductivity measurement of doped polyaniline powder precipitated in THF as dispersing medium gave a value of 0.13 S cm-1 when the emeraldine base form of polyaniline is fully protonated. The polyaniline salt sample is characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction, UV-Visible spectra and FTIR spectra.

Preparation and Characterization of PET/MMT Nanocomposition Modified by MDI

2014 ◽  
Vol 904 ◽  
pp. 7-9
Author(s):  
Xiao Hua Gu ◽  
Xi Wei Zhang ◽  
Bao Yun Xu ◽  
Peng Zeng
Keyword(s):  
Thermal Stability ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Organic Montmorillonite ◽  
Polymerization Method ◽  
Thermal Stability Of

In this paper, the diphenyl methane diisocyanate (MDI) was used to modify montmorillonoid (MMT) and got the organic montmorillonite (OMMT), which was used with the monomers of PET by in situ polymerization method to prepare PET/MMT nanocomposition. The OMMT was analyzed by the X ray diffraction (XRD) to test the change of the spacing layer. Dispersion of MMT in the PET/MMT nanocomposites were studied with XRD and SEM and by means of thermogravimetric analyzer (TGA) on the thermal stability of PET/MMT nanocomposites. The results showed that, MDI modified MMT successfully, and the compatibility of MMT and PET was increased .

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

Spectral Investigation on the Growth and Characterization of NLO Crystals of Thiourea Succinic Acid Single Crystal.

2015 ◽  
Vol 2 (2) ◽  
pp. 70-73
Author(s):  
Kannan.P ◽  
Thambidurai.S ◽  
Suresh.N
Keyword(s):  
Single Crystal ◽  
Succinic Acid ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Dta Analysis ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.

Preparation and Characterization of the High Molecular Weight [3H]Hyaluronic Acid

1992 ◽  
Vol 57 (10) ◽  
pp. 2151-2156 ◽  
Author(s):  
Peter Chabreček ◽  
Ladislav Šoltés ◽  
Hynek Hradec ◽  
Jiří Filip ◽  
Eduard Orviský
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
High Molecular Weight ◽  
Methyl Bromide ◽  
High Performance ◽  
Hydrogen Atoms ◽  
Isolation And Characterization ◽  
Labelling Procedure ◽  
Enzymatic Depolymerization

Two methods for the preparation of high molecular weight [3H]hyaluronic acid were investigated. In the first one, hydrogen atoms in the molecule were replaced by tritium. This isotopic substitution was performed in aqueous solution using Pd/CaCO3 as the catalyst. In the second method, the high molecular weight hyaluronic acid was alkylated with [3H]methyl bromide in liquid ammonia at a temperature of -33.5 °C. High-performance gel permeation chromatographic separation method was used for the isolation and characterization of the high molecular weight [3H]hyaluronic acid. Molecular weight parameters for the labelled biopolymers were Mw = 128 kDa, Mw/Mn = 1.88 (first method) and Mw = 268 kDa, Mw/Mn = 1.55 (second method). The high molecular weight [3H]hyaluronic acid having Mw = 268 kDa was degraded further by specific hyaluronidase. Products of the enzymatic depolymerization were observed to be identical for both, labelled and cold biopolymer. This finding indicates that the described labelling procedure using [3H]methyl bromide does not induce any major structural rearrangements in the molecule.

Mechanical and thermal characterization of grafted PP-NCC nanocomposites

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Properties ◽  
Interfacial Adhesion ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Twin Screw ◽  
Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

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